insulation boards connecticut

[Pologuy9906]

Looking for boards in Connecticut

[UtahBeehiver]

do a google search for refractory supplies in CT, ie Harbison - Walker

[Pologuy9906]

Thanks. They have 3" x 12 x 36 in a case for $155. I can pick it up. I should use dry refractory cement and mason sand mixture to level boards? Or should level the bricks on the insblock?

[mongota]

Best (and often easiest) to start with level. Level the slab and install the insulation on the level slab. Then set the bricks on the level insulation.

[UtahBeehiver]

Use a mix of 50% fire clay and 50% sand add water to a peanut butter consistency troweled on with a 1/4 - 3/8" square notched tile trowel. Need to move fast, CaSi will absorb water fast. Some builders coat the "bottom" of the Ca Si with margarine (no kidding), or a cheap paint to make the CaSi less water absorbent. It is best to get the insulation as level as possible then install the fire bricks, you may need to adjust some of the fire bricks as well with a dry mix of the 50/50.

There has been much discussion about placing the CaSi directly to the concrete slab since it can absorb water which will affect oven performance. Here are some suggested remedies:

1. Install a weep hole during the hearth pour so errant water can migrate out.
2. Install CaSi off the hearth, One builder used concrete 1" pavers, I used FoamGlas (expensive but water proof), V or Pcrete 1st layer, etc.
3. Vapor or water barrier, although this can be a double edge sword if water gets in, it will hold it in.

I am sure there are others, these just come to mind. Good luck

[david s]

I like to make the surface of the supporting slab sloping slightly down from the centre to the outsides. This discourages water from migrating under the floor bricks and pooling in the centre. Should it do so and to assist its removal as Russell suggested a weep hole or two through the supporting slab helps.If you encounter difficulty with the sand/fiteclay levelling mix drying out too fast on application, simply use it dry. If any floor bricks require removal at a later stage it makes this task easier if they're not stuck down.
Regarding a vapour barrier between the slab and insulation, you can omit it if you want. The same applies for a waterproof coating over the dome (if doing an igloo). This is why I like to seal the whole thing up, but have a drain hole at the bottom and also a vent in the sealed igloo. Water vapour will travel away from any heat applied to it ,but it needs an escape. The alternative, and that used by Traditional Italian ovens, in the absence of modern materials is to keep the whole thing porous to allow for the migration of water through the whole structure. Not as elegant a solution IMHO